The gallbladder is a small, pear-shaped, hollow organ located just below the liver on the right side of the body. The gallbladder forms a storage reservoir for bile, also known as "bile", which is related to the origin of its name. It is a muscular organ that contracts when bile is required, pushing the bile through the cystic duct. The main function of the gallbladder is to store and concentrate bile (which is produced in the liver) and to release bile into the digestive system.
What is bile?
Bile is a greenish-brown alkaline liquid (made up of waste products, cholesterol, and bile salts). Bile is not a digestive enzyme, but bile salt works in a similar way, emulsifying large droplets of fat. The main function of bile in the digestive system is to break down fats. Bile is secreted from the gallbladder (where it is stored) and then travels to the small intestine in response to a hormone called cholecystokinin (which is released when food enters the small intestine from the stomach). As soon as bile enters the duodenum (the first section of the small intestine), it begins to break down fats that have entered the body, as well as fat-soluble vitamins, improving the solubility of digested fat and facilitating its absorption.
Bile is what gives stool its brown color. The final entry site for bile is feces through the anus.
The gallbladder is located in front of the duodenum (the first section of the small intestine). It is about an inch wide and 3 inches long and tapers at one end where it joins the cystic duct. It is capable of storing 30 to 50 cubic centimeters (cm) of a liquid called bile.
The gallbladder is divided into three parts, including:
- The bottom is a large, rounded base that stores bile juices; the fundus includes the distal (far) part of the gallbladder, which is at an angle, forcing you to look at the abdominal wall.
- The body is the part of the gallbladder that begins to shrink towards the neck.
- The neck is the area where the gallbladder continues to narrow, narrowing as it joins the cystic duct (which leads to the bile duct).
At the neck of the gallbladder there is an area of folded tissue called the Hartmann's sac. This is an area located at the junction of the neck of the gallbladder and the cystic duct where gallstones usually get stuck, causing a decrease in the flow of bile ( cholestasis ).
There are several layers of the gallbladder, including:
- The epithelium is the thin layer of cells that lines the inside of the gallbladder.
- Lamina itself : a layer of connective tissue; When this layer combines with the epithelium, it forms the mucous membrane (the membrane that lines the body cavities and lines the organs)
- Muscularis is a layer of smooth muscle tissue that allows the gallbladder to contract to release bile into the bile duct.
- The perimuscular is the fibrous layer of connective tissue that surrounds the muscle layer.
- The serous membrane is a smooth membrane that forms the outer covering of the gallbladder.
The outer layer of the gallbladder floor and other surfaces of the gallbladder, those that are not in direct contact with the liver, are covered with a tissue called serosa. The serous membrane is a type of tissue that lines the internal cavities and forms a smooth, two-layered membrane that is lubricated with fluid. Serosa contains blood vessels and lymphatic vessels (vein-like vessels that are part of the lymphatic system). The function of the lymphatic vessels is to transport lymphatic fluid from the lymph nodes .
The surfaces of the gallbladder that are in contact with the liver are not covered with a serous membrane, but are covered with connective tissue.
The gallbladder is located below (below) and posterior (behind) the liver in the upper right quadrant (cut) of the abdomen. It is located in front of the duodenum (the first section of the small intestine). The gallbladder is connected to the liver through ducts known as the biliary tract.
The gallbladder is attached to the digestive system by a hollow duct system called the gallbladder. The gallbladder, bile ducts (the tubules that carry bile), and associated structures (which are responsible for the production and transport of bile) make up what's called the "bile system." This is sometimes called the biliary tract.
Through this system, bile flows from the liver (where liver cells produce and secrete bile) into a system of ducts located inside and outside the liver, which allow bile to drain from:
- Right and left hepatic ducts
- Drain into the common hepatic duct
- Bile leaves the common hepatic duct, which joins the cystic duct from the gallbladder to form the common bile duct.
- The common bile duct runs from the liver to the first section of the small intestine ( duodenum ), where some of the bile is excreted from the body to help break down fat. Note that 50% of the bile that passes through the common bile duct is stored in the gallbladder.
After eating, the cholecystokinin hormone is released; This stimulates the secretion of bile and the bile begins to break down fats in the digestive system.
Examples of anatomical variations in the gallbladder include :
- Agenesis is the absence of the gallbladder.
- A double gallbladder with a common duct or two separate cystic ducts may be seen.
- The Phrygian cap is the most common congenital (present at birth) anatomical variation of the gallbladder associated with fundus abnormalities.
The gallbladder has several important functions, including :
- To store and concentrate bile.
- To respond to intestinal hormones (such as cholecystokinin) to empty and replenish bile stores.
- Contribute to the regulation of the composition of bile (percentage of water, bile salts, etc.)
- To control the flow of bile to the small intestine.
- Contract (secretion of bile into the biliary tract and duodenum)
Gallbladder contractions are caused by several factors, including:
- Fatty foods combined with bloating (stomach bulging from eating too much)
- Cholecystokinin (CCK) release from the duodenum
Function of the biliary system.
There are several important functions of the biliary system, including :
- Drain waste products from the liver into the first section of the small intestine (called the duodenum).
- The secretion of bile (controlled release), which helps in the digestion of fats during digestion.
Bile has two main functions, including:
- Take away the waste
- Break down fats
Common gallbladder conditions can include infection, stones, inflammation, or blockage of the gallbladder .
Gallstones (gallstones) are pebble-shaped deposits of bile in the gallbladder. They can be very small (about the size of a grain of sand) or as large as a golf ball. They can accumulate as a single stone in the gallbladder or as many stones of various sizes. There are two types of gallstones, including :
- Cholesterol gallstones (made up of undissolved cholesterol, are yellow in color and are the most common type)
- Pigmented gallstones (dark brown or black stones caused by too much bilirubin in the bile)
Other conditions include :
- Cholecystitis (inflammation of the gallbladder)
- Chronic (long-term) acalculous gallbladder disease (a condition associated with the inability of the gallbladder to contract and empty bile)
- Gallbladder gangrene (death of gallbladder tissue, which is the most common symptom in untreated conditions, such as gallstone disease, or in people with diabetes)
- Gallbladder abscess
- Birth defects (conditions that are present at birth) of the gallbladder.
- Sclerosing cholangitis (a progressive condition of the liver and gallbladder that causes scarring and obstruction of the bile ducts)
- Bile duct or gallbladder tumors
After a diagnosis of gallstones (or other gallbladder disorders) is made, most people with symptoms have their gallbladder removed. This procedure is called a cholecystectomy . This procedure is most often done with laparoscopic surgery (using a telescope with a camera inserted into a very small incision). Laparoscopic surgery is also called minimally invasive surgery because of the small incision. Cholecystectomy is one of the most common robotic surgery procedures today. One of the most common surgeries performed around the world is gallbladder removal (cholecystectomy) as a treatment for gallstones .
Tests performed to diagnose gallbladder conditions may include:
- Liver enzyme tests are blood tests that may be elevated if inflammation is severe and may also indicate the possibility of gallstones.)
- A complete blood count (CMP) metabolic panel can show an increase in bilirubin levels if the bile duct is blocked.
- A complete blood count (CBC) can indicate acute cholecystitis when the white blood cell count is high.
- Ultrasound (the preferred test for cholecystitis, can show with certainty if there are signs of inflammation and / or gallstones )
- Computed tomography (CT) is a detailed X-ray image of the gallbladder.
- Magnetic resonance imaging (MRI) is often done during an emergency exam when a person complains of unexplained abdominal pain .
- Abdominal x-ray
- Endoscopic retrograde cholangiopancreatography (ERCP) includes endoscopy. A tube with a camera, which is inserted into the throat and down the esophagus to the stomach and then into the small intestine, is injected into the ducts of the gallbladder, liver and pancreas so that the organs can be seen clearly in X-rays.
- Hepatobiliary iminodiacetic acid (HIDA) scan with cholecystokinin (CCK) is a test that involves the administration of cholecystokinin to stimulate the gallbladder. Next. Photographs of the gallbladder are taken before and after CCC to assess how well the gallbladder is contracting.